Compare the graphs of f(x)=−x−−√

and g(x)=−x−−√3
. Which of the following features about the graphs is true?

(1 point)
Responses

The graphs have the same ranges.
The graphs have the same ranges.

The graphs have the same domains.
The graphs have the same domains.

The graphs are both increasing.
The graphs are both increasing.

The graphs are both decreasing.

1 answer

To compare the graphs of the functions \( f(x) = -\sqrt{x} \) and \( g(x) = -\sqrt[3]{x} \), let’s analyze their domains, ranges, and behavior (increasing or decreasing).

  1. Domains:

    • For \( f(x) = -\sqrt{x} \), the domain is \( [0, \infty) \) because the square root is defined for non-negative values.
    • For \( g(x) = -\sqrt[3]{x} \), the domain is \( (-\infty, \infty) \) because cube roots are defined for all real numbers.
    • Therefore, the graphs do not have the same domains.
  2. Ranges:

    • The range of \( f(x) = -\sqrt{x} \) is \( (-\infty, 0] \) since \( -\sqrt{x} \) takes on all non-positive values as \( x \) varies over its domain.
    • The range of \( g(x) = -\sqrt[3]{x} \) is also \( (-\infty, 0] \) because, regardless of whether \( x \) is positive, negative, or zero, \( -\sqrt[3]{x} \) can still take values in this range.
    • Therefore, the graphs have the same ranges.
  3. Behavior (increasing or decreasing):

    • The function \( f(x) = -\sqrt{x} \) is a decreasing function because as \( x \) increases, \( -\sqrt{x} \) decreases.
    • The function \( g(x) = -\sqrt[3]{x} \) is also a decreasing function for the same reason.
    • Therefore, both functions are decreasing.

Based on this analysis, the correct responses are:

  • The graphs have the same ranges.
  • The graphs are both decreasing.

So, the responses that are true are:

  1. The graphs have the same ranges.
  2. The graphs are both decreasing.

You could select the first statement as a response since it matches your options provided.